[Intel-gfx] [RFC 2/6] drm/i915: Add tiled framebuffer modifiers

[Rob Clark]

On Mon, Feb 2, 2015 at 4:41 AM, Daniel Vetter <daniel at ffwll.ch> wrote:
> On Fri, Jan 30, 2015 at 05:36:54PM +0000, Tvrtko Ursulin wrote:
>> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
>>
>> To be used from the new addfb2 extension.
>>
>> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
>> ---
>>  include/uapi/drm/i915_drm.h | 13 +++++++++++++
>>  1 file changed, 13 insertions(+)
>>
>> diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
>> index 6eed16b..a7327fd 100644
>> --- a/include/uapi/drm/i915_drm.h
>> +++ b/include/uapi/drm/i915_drm.h
>> @@ -28,6 +28,7 @@
>>  #define _UAPI_I915_DRM_H_
>>
>>  #include <drm/drm.h>
>> +#include <uapi/drm/drm_fourcc.h>
>>
>>  /* Please note that modifications to all structs defined here are
>>   * subject to backwards-compatibility constraints.
>> @@ -1101,4 +1102,16 @@ struct drm_i915_gem_context_param {
>>       __u64 value;
>>  };
>>
>> +/** @{
>> + * Intel framebuffer modifiers
>> + *
>> + * Tiling modes supported by the display hardware
>> + * to be passed in via the DRM addfb2 ioctl.
>> + */
>> +/** None */
>> +#define I915_FORMAT_MOD_NONE fourcc_mod_code(INTEL, 0x00000000000000L)
>> +/** X tiling */
>> +#define I915_FORMAT_MOD_X_TILED      fourcc_mod_code(INTEL, 0x00000000000001L)
>
> One thing I wonder here is whether we should have a modifier for each
> physical layout (tiling modes do change slightly between hw) or whether we
> should just continue to assume that this is Intel-specific and add a
> disclaimer that the precise layout depends upon the actual intel box
> you're running on?

I'd kind of lean towards different modifiers per physical layout..
that seems more useful for cases where nvidia/amd support some of the
formats for buffer sharing..

BR,
-R

> Leaning towards your approach, worst case we get to write some code to
> de-alias layout modifiers with established cross-vendor layouts (if they
> ever happen). Just want to make sure that we've thought about this. Adding
> Rob&dri-devel for this.
> -Daniel
>
>> +/** @} */
>> +
>>  #endif /* _UAPI_I915_DRM_H_ */
>> --
>> 2.2.2
>>
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>
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> +41 (0) 79 365 57 48 - http://blog.ffwll.ch